- `stringify` (Boolean): If `false`, the pixel objects will not be
stringified.
- `concat` (Boolean): If `false`, the pixel objects will not be joined
together.

Pixel asciifier options:

- `pixels` (Array|String): An array or string containing the characters
used for converting the pixels in strings
(default: `" .,:;i1tfLCG08@"`).
- `reverse` (Boolean): If `true`, the pixels will be reversed creating a
*negative image* effect (default: `false`).
- `colored` (Boolean): If `true`, the output will contain ANSI styles
(default: `true`).
- `bg` (Boolean): If `true`, the **background** color will be used for
coloring (default: false).
- `fg` (Boolean): If `true`, the **foreground** color will be used for
coloring (default: true).
- `white_bg` (Boolean): Turn on the white background for transparent
pixels (default: `true`).
- `px_background` (Object): An object containing the `r` (red), `g`
(green) and `b` (blue) values of the custom background color.

Other options:

- `image_type` (String): Use this to explicitely provide the image type.
- `stringify_fn` (Function): A function getting the `pixels` matrix and
the `options` in the arguments. Use this option to implement your own
stringifier.